FBI examines Wite-Outed invoices, envelopes that were cash-stuffed in David Rivera investigation

A key witness in a federal grand jury case involving U.S. Rep.David Rivera is still missing, but she left important evidence behind for investigators: at least four envelopes that had been stuffed with unreported campaign cash.

Ana Alliegro, a Republican political operative, delivered the cash-stuffed envelopes to a Hialeah mail house that sent out fliers in a congressional race against a Rivera political rival, the mail house owner told the FBI.

The FBI has the envelopes to check for fingerprints and handwriting comparisons.

Also in the hands of FBI agents: at least six invoices initially made out to the attention of David Rivera — all marked paid “cash” — to cover the mailings for Democratic primary challenger Justin Lamar Sternad, a suspected Rivera straw-man candidate. The congressman demanded that his name be removed from the invoices with Wite-Out, documents and interviews show.

Alliegro went missing two weeks ago, shortly after her computer was seized by FBI agents and just hours before she was scheduled to talk to a federal prosecutor about her involvement in the Rivera-Sternad operation. She also had been jailed by Miami cops on an old suspended driver-license warrant.

“Am I worried? Yes,” Mauricio Padilla, her lawyer, said Friday. “I have not heard or seen her. This has never happened to me before.”

Enrique “Rick” Yabor, who represents Sternad, said he and his client would not comment.